What is the flexor retinaculum and what does it form?

The flexor retinaculum is a thickened band of deep fascia that spans the anterior concavity of the carpus, converting it into the carpal tunnel. It attaches medially to the pisiform and hook of hamate, and laterally to the tubercle of scaphoid and crest of trapezium.

What structures pass through the carpal tunnel?

Within the carpal tunnel, the structures include the flexor digitorum superficialis and profundus tendons (within the ulnar bursa), flexor pollicis longus tendon (within the radial bursa), and the median nerve.

What is the function of the palmar aponeurosis?

The palmar aponeurosis is a thick, triangular fibrous sheet that protects deep structures (like vessels, nerves, and tendons) and stabilizes the skin to improve grip in the palm.

What is Dupuytren’s contracture and how does it affect the hand?

Dupuytren’s contracture is a condition involving progressive fibrosis and thickening of the medial part of the palmar aponeurosis. It most commonly affects the ring and little fingers, causing flexion deformity of the proximal and middle phalanges, while the distal phalanges are typically unaffected.

What are fibrous flexor sheaths and what is their role?

Fibrous flexor sheaths are fibrous tunnels formed by thickened deep fascia on the anterior surface of digits. They enclose and protect the long flexor tendons, and their structure includes annular and cruciform fibers that act as pulleys to prevent tendon bowstringing during finger flexion.

What causes trigger finger and where does it commonly occur?

Trigger finger is caused by localized thickening of a flexor tendon that catches within the fibrous sheath, leading to locking in flexion and snapping on extension. It most commonly occurs at the A1 pulley of the fibrous sheath.

How is the palmar aponeurosis connected to other structures in the palm?

The palmar aponeurosis has several connections: its apex blends with the flexor retinaculum and palmaris longus tendon; its base divides into four slips that attach to fibrous flexor sheaths; and its medial border continues with hypothenar fascia, while the lateral border continues with thenar fascia.

Deep Palmar Fascia – Flexor Retinaculum & Aponeurosis

❓ Frequently Asked Questions